The present invention relates to an improved spring tracer for duplicating machine for punched and laser keys.
As shown in FIG. 1, the prior art U.S. Pat. No. 5,833,406 discloses a tracer for punched and laser keys which comprises a feeler 28′ which is secured on a carriage 18′, and held by a self-centering chuck 56′, and engaged with a shaft 58′ which is slidably engaged with a an insulated sleeve 60′ which is engaged with a tubular support 62′. Such tubular support is supported by the body of the carriage 18′ and is at its lower end engaged with a ring nut 64′ which is at its one side formed with a plurality of equiangular radial notches for snap engagement of a ball 66′, which are mounted within the body of the carriage 18′, to form a regulation device, for rotation of the ring nut 64′, in order to move feeler 28′ upward or downward. The construction of such a regulation device is complicated, and difficult to manufacture. Furthermore, the upper end of the shaft 58′ is provided with a fixed guide which is provided with a pair of confronting slanting guides at its bottom, for engaging or disengaging with a pair of confronting slanting grooves provided on the top of a ring nut 70′, and a spring sleeve is provided beneath the ring nut 70′, and secured on a tubular support 62′. A compression spring 72′ is provided between the spring sleeve and the tubular support 62′, and is biased between the spring sleeve and the carriage 18′. The ring nut 70′is rotatably movable between two angular end positions. When in one of these two positions the ring nut 70′ provides axially rigid counteraction to the tubular support 62′, whereas when in the other it allows the sleeve 60′ to undergo a predetermined extent of upward axial travel relative to the carriage 18′ against the reaction of the compression spring 72′, so that the feeler 28′ can be moved to a predetermined extent against the reaction of an inner compression spring engaged with the insulated sleeve 60′. In such tracer construction, it needs two compression springs, and hence its construction is complicated. The compression spring 72′ will lose its biasing force if it is broken down due to long duration of being compressed. A known toggle clamp will be used to secure the whole carriage if the feeler is to be secured to a required elevation, i.e. an extension spring will be used to move a movable support in order to secure the carriage. Such toggle clamp will enable the whole construction of the feeler to become more complicated, and form a multi-action line structure on the whole which will result in a relatively large processing error, and reduce the duplicating precision of the duplicating machine for punched and laser keys.
The present invention aims at eliminating the above disadvantages and provides an improved spring tracer for duplicating machine for punched and laser keys which can increase the duplicating precision and simplify the construction of the duplicating machine by means of effecting the regulating action, the securing action, and the biasing action of a duplicating machine in a common longitudinal axis.
In a preferred aspect of the present invention, the improved spring tracer for duplicating machine for punched and laser keys comprises a longitudinal spindle suspended from an end of a synchronous lateral lever having the other end laterally connected to a longitudinal shaft for a duplicating tool in parallel with the longitudinal spindle, which can be longitudinally slidably secured on a body portion in accordance with a common longitudinal axis of the longitudinal spindle; a spring-loaded tracer engaged in the inner lower end of the longitudinal spindle for biasing a tracer stylus against an original punched or laser key by means of the spring force for tracing the depths of the key teeth of the original punched key in accordance with the said common longitudinal axis; and a regulating sleeve rotatably secured at the outer lower end of the longitudinal spindle for regulating the elevation of the spring-loaded tracer in accordance with the said common longitudinal axis, in order that a regulating action, a securing action and a biasing action can be effected in a common longitudinal axis, so as to increase the duplicating precision and simplify the construction of the duplicating machine for punched and laser keys.